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Core 2

Posted on 8 Feb 2008 at 12:10

While AMD proceeds with its relatively new 65nm manufacturing process, Intel has already left 65nm behind in favour of 45nm: it's currently the only semiconductor manufacturer in the world able to produce 45nm chips in volume. This puts Intel - on paper at least - a product generation ahead of Advanced Micro Devices.

Power consumption

Anyone with any experience of Intel-based PCs is likely to have not one but three pretty large heatsinks on their motherboard. The first is for the processor, of course, but the other two are for the supporting chipset, with one on the south bridge and often a larger one on the north bridge, which incorporates the MCH. If you've ever been foolhardy enough to touch a passive north-bridge heatsink on an Intel system, the resulting burn on your finger will tell you they consume a significant amount of power. It isn't at the same level as a CPU, but the combined power consumption of the chipset can reach 15W or so - more than the total for some complete VIA systems. However, that's offset by the impressively low power consumption of Core 2 processors, particularly the 45nm-based QX9650, despite its hefty 126W rated TDP (thermal design power).

The QX9650 is the only 45nm desktop processor Intel currently offers. With its massive transistor count and 3GHz clock speed, power consumption when the processor is maxed out with all four cores at 100% utilisation should be very high. In practice, its raft of intelligent power-saving measures meant the average power consumption of our test system was an impressive 98W at idle, and 160W at full pelt. Although this is higher in absolute terms than Phenom, the much higher benchmark score gives a superior score in terms of performance per watt.

Performance

There's little doubt that Intel still comprehensively rules the roost in terms of outright, money-no-object speed. Even disregarding the design finesse that Intel's processor engineers have endowed the Core 2 range with, the company has pulled ahead by throwing lots of very tiny transistors at the problem. The result is that the QX9650 has three times the total cache complement of the Phenom 9000 series, with 12MB L2 cache in total split between the two separate pairs of cores in the physical package - 6MB per pair. And with up to 100% of each 6MB chunk available to one core at a time, single-threaded code - which still comprises the lion's share of performance-hungry applications - gets a massive boost. That said, there are diminishing returns compared to the 8MB total (4MB per pair) in the previous-generation quad-core parts, including the Core 2 Quad Q6600.

The Extreme Edition QX9650 may cost more than £500, but given its benchmark result of 2.27 overall, there are plenty of people who'd deem it well worth the money. Even the Core 2 Quad Q6600 - now only about £140 - still outperforms the Phenom 9500 in our benchmarks, giving Intel the edge on the desktop in every possible category: bang per buck, performance per watt and outright speed.

Prospects

Intel didn't let up when it pulled ahead of AMD with the release of the Core microarchitecture. It's driven a massive wedge into the performance gap and carried on hammering, resorting to something akin to strutting where its newest processors are concerned. We've already seen its next-generation QX9770 (web ID: 141768), which extends the lead even further, albeit at the expense of slightly lower performance-per-watt figures. The 9770 runs at 3.2GHz and sports the same 1,600MHz FSB as the newer Xeon parts. It's a cheeky move on Intel's part to send samples out to press for testing without giving a release date or pricing, but it certainly serves to highlight - or give the impression of highlighting - the technology lead it holds.